AbstractIntroductionIncreasingly, early‐stage non–small cell lung cancer (NSCLC) is treated with stereotactic body radiation therapy (SBRT). Although treatment is generally effective, a small subset of tumors will recur because of radioresistance. Preclinical studies suggested PI3K‐AKT‐mTOR activation mediates radioresistance. This study sought to validate this finding in tumor samples from patients who underwent SBRT for NSCLC.MethodsPatients with T1‐3N0 NSCLC treated with SBRT at our institution were included. Total RNA of formalin‐fixed paraffin‐embedded tumor biopsy specimens (pretherapy) was isolated and analyzed using the Clariom D assay. Risk scores from a PI3K activity signature and four published NSCLC signatures were generated and dichotomized by the median. Kaplan–Meier curves and Cox regressions were used to analyze their association with recurrence and overall survival (OS). The PI3K signature was also tested in a data set of resected NSCLC for additional validation.ResultsA total of 92 patients were included, with a median follow‐up of 18.3 months for living patients. There was no association of any of the four published gene expression signatures with recurrence or OS. However, high PI3K risk score was associated with higher local recurrence (hazard ratio [HR], 11.72; 95% CI, 1.40–98.0; p = .023) and worse disease‐free survival (DFS) (HR, 3.98; 95% CI, 1.57–10.09; p = .0035), but not OS (p = .49), regional recurrence (p = .15), or distant recurrence (p = .85). In the resected NSCLC data set (n = 361), high PI3K risk score was associated with decreased OS (log‐rank p = .013) but not DFS (p = 0.54).ConclusionsThis study validates that higher PI3K activity, measured by gene expression, is associated with local recurrence and worse DFS in early‐stage NSCLC patients treated with SBRT. This may be useful in prognostication and/or tailoring treatment, and merits further validation.
Proton craniospinal irradiation with bevacizumab and pembrolizumab for leptomeningeal disease: a case report
BACKGROUND: Functional gallbladder disorder is most commonly defined by biliary colic and low ejection fraction (EF) on cholescintigraphy. Biliary hyperkinesia is a controversial type of functional gallbladder disorder, and its definition and the role of cholecystectomy in treating functional gallbladder disorder remains unclear. STUDY DESIGN: We conducted a retrospective review of patients who underwent cholecystokinin-stimulated cholescintigraphy and cholecystectomy at 3 Mayo Clinic sites between 2007 and 2020. Eligible patients were 18 years or older, presented with symptoms of biliary disease, had an EF greater than 50%, underwent cholecystectomy, and had no evidence of acute cholecystitis or cholelithiasis on imaging. We used receiver operating characteristics curve analysis to identify the optimal cutoff value that predicted symptom resolution within 30 days of cholecystectomy. RESULTS: A total of 2,929 cholecystokinin-stimulated cholescintigraphy scans were performed during the study period; the average EF was 67.5% and the median EF was 77%. Analyzing those with EFs greater than or equal to 50% yielded 1,596 patients with 141 (8.8%) going on to have cholecystectomy. No significant differences were found in age, sex, BMI, final pathology between patients with and without pain resolution. Using a cutoff EF of 81% was significantly associated with pain resolution after cholecystectomy (78.2% for EF greater than or equal to 81% vs 60.0% for EF less than 81%, p = 0.03). Chronic cholecystitis was found in 61.7% of the patients on final pathology. CONCLUSIONS: We determined that an EF cutoff of 81% is a reasonable upper limit of normal gallbladder EF. Patients with biliary symptoms and an EF greater than 81% but no evidence of biliary disease on ultrasound or scintigraphy can be classified as having biliary hyperkinesia. Based on our findings, we recommend cholecystectomy for this patient population.
Abstract 12681: GWAS Meta-Analysis in SCAD, a Women Predominant Ischemic Heart Disease, Reveals Common Variants and Genes Related to Artery Integrity and Tissue-Mediated Coagulation
Introduction: Spontaneous coronary artery dissection (SCAD) is an understudied cause of acute myocardial infarction due to hematoma formation in coronary arteries primarily affecting women. It is not known to what extent SCAD is genetically distinct from other cardiovascular diseases, including atherosclerotic coronary artery disease (CAD). Methods and Results: Through a meta-analysis of 8 GWAS (1917 cases, 9292 controls of European ancestry), we identified 17 risk loci, including 12 new. Functional annotations pointed at enrichment in enhancer marks of arteries, specifically smooth muscle cells, and strong candidate genes, such as tissue factor gene ( F3 ) on Chr1 near rs1146473 (OR=1.32, P=5.8 х10 -9 ). F3 is novel for SCAD or any cardiovascular disease. The risk allele correlated with F3 lower expression in arteries, supporting a mechanism consistent with hematoma formation. Bayesian gene regulatory networks constructed from expression and genetics data indicated the extracellular matrix organization in arteries as the biological function where most prioritized genes clustered (e.g. COL4A1/A2, HTRA1, and TIMP3 ). Overall, we report substantial polygenicity for SCAD (LDSC: h 2 SNP = 0.71 ± 0.11) and shared genetics with several neurovascular diseases (e.g intracranial aneurysm). Intriguingly, for 6 loci, colocalization analyses showed that SCAD and CAD are likely to share the same causal variants but involve opposite risk alleles (e.g COL4A1/A2 ). In addition, a negative genetic correlation was found between SCAD and CAD (rg=-0.12; P=3.7х10 -3 ), including after conditioning on BP (mt-COJO: rg CAD/SBP =-0.19, P=4.6х10 -6 ). Mendelian randomization analyses indicated higher BP to associate with increased risk for SCAD (beta IVW-SBP =0.05, P=7.6х10 -6 , beta IVW-DBP =0.10, P=1.9х10 -6 ) and CAD (beta IVW-SBP =0.04, P=8.6х10 -49 ; DBP: beta IVW-DBP =0.06, P=1.6х10 -44 ) but not BMI, lipids, or type 2 diabetes, which we confirmed as genetic risk factors for CAD Conclusions: Our results set the stage for future investigation of novel biological pathways relevant to both SCAD and CAD and potential therapeutic and preventive strategies specifically targeting this ischemic disease predominantly affecting women.
Efficacy and safety study of neoadjuvant efineptakin alfa (NT-I7) and pembrolizumab in recurrent glioblastoma.
TPS2085 Background: Glioblastoma (GBM) is the most common and aggressive form of brain tumor in adults. Despite maximal surgical resection, irradiation, and chemotherapy, median overall survival (OS) remains at only 30 weeks for recurrent GBM (rGBM) patients, emphasizing the need for novel treatments. GBM tumors are immunologically ‘cold,’ in that they have an immune-suppressive microenvironment with a low number of tumor-infiltrating lymphocytes (TIL). Interleukin 7 (IL-7) plays a key role in T cell development and survival. The physiological level of IL-7 increases to stimulate T cell expansion in lymphopenic condition. Previous studies have shown that lymphopenic GBM patients have shorter survival. However, their IL-7 levels are unexpectedly low. Efineptakin alfa (NT-I7), a long-acting IL-7, has been shown to increase effector CD8 T cells and reduce suppressor T-regulatory cells in murine GBM models, with subsequently improved OS. Further, we recently completed a Phase I study which showed that NT-I7 is safe, well- tolerated, and increased absolute lymphocyte counts (ALC) in newly diagnosed GBM patients. Phase II dosing was determined through this Phase I study reaching maximum tolerated dose. Thus, we hypothesized that NT-I7 may reverse GBM-associated immune suppression and potentiate the effect of an immune checkpoint inhibitor, leading to an increase in TILs and improved survival. Our preliminary data suggests that combining NT-I7 with pembrolizumab, an anti-PD-1 antibody, improves survival in murine glioma models. The purpose of this study is to evaluate the safety and efficacy of combining NT-I7 and pembrolizumab in rGBM patients. Methods: This is an open-label single arm one-stage Phase II study of NT-I7 and pembrolizumab as neoadjuvant and adjuvant therapy with surgery for adult patients with rGBM. We plan to enroll 30 evaluable patients, including a 6-patient safety run-in. Key eligibility criteria include candidates willing to undergo clinically indicated resection or biopsy, age ≥ 18 years, Karnofsky performance status ≥ 70, and dexamethasone dose > 2 mg/day ≤ 2 days prior to registration. The primary endpoint is a 9-month OS rate. Secondary endpoints include progression-free survival, objective response rate, changes in ALC, and adverse events profile. The correlative endpoints include studies to assess the anti-glioma immune response, changes in T cell subsets, T cell effector function, cytokine analysis, and immunohistochemical analysis of GBM tissue. Longitudinal cerebrospinal fluid proteomics is optional. This study opened on 1/20/2023. Two of the planned 30 patients had been enrolled by submission on 2/14/2023. Clinical trial information: NCT05465954 .
Efficacy of function-enhanced, re-activatable, dual-specific CAR T cells pre-loaded with oncolytic virus for immunotherapy of high-grade glioma.
2062 Background: While cancer therapeutics have made tremendous progress within the past several decades, this benefit has not been seen in many primary cancers of the brain. Particularly confounding have been high-grade gliomas (HGG), which retain a dismal prognosis. Currently, novel therapies are being explored to rise to this unmet, critical need. One such therapy are CAR T cells, immune cells which have been engineered to target malignancy-specific antigens. Unfortunately, the efficacy of CAR T cell therapies against solid tumors is significantly limited, in large part due to impaired expansion/persistence in the immune suppressive tumor microenvironment (TME). Here we show that in vivo reactivation of CAR T cells through their native T Cell Receptor (TCR) by an oncolytic virus (OV) has therapeutic benefit in HGG. Methods: An EGFRvIII third-generation MSGV1 retroviral CAR construct containing the CD28, 4-1BB, and CD3z moieties, in tandem with the scFv derived from the human monoclonal antibody 139 and the marker Thy1.1 (38) was used to generate our CAR T cells. C57Bl/6 mice were used for in vivo experiments and both B16- and CT2A-EGFRvIII murine glioma cell lines were injected in the brain to model HGG. OVs and CAR T cells were given systemically by tail vein. OVs used include reovirus, vesicular stomatitis virus, and adenovirus. Results: By using OV in combination with EGFRvIII CAR T cells, we were able to generate a CD8 CAR population with TCR specificity for both the EGFRvIII and OV epitopes. These dual-specific (DS) CAR T expressed a memory phenotype and persisted for much longer than conventional CAR T cells. Further, we showed that these DS CAR T cells are more cytotoxic and can respond more rapidly than their conventional counterparts. We created a novel delivery mechanism for this combination OV + CAR T therapy using virus-loaded CAR T cells to bypass initial antiviral clearance from the immune system. Treatment with these OV-loaded CAR T cells lead to significant benefit in mice with HGG tumors which could be further enhanced by a systemic boost with OV, which rapidly re-activated DS CAR T cells against tumor and resulted in long-term cures of greater than 80% of treated animals. Conclusions: These promising results show that DS CAR T cells can overcome the critical therapeutic challenge of CAR T as a treatment for solid tumors. Given these promising results, we will go on to develop a clinical trial in which CAR T cells will be pre-loaded with OV and administered intravenously to patients with HGG, followed by systemic boosting with virus to re-activate DS CAR T cells against their tumor.
Implementation of Bedaquiline, Pretomanid, and Linezolid in the United States: Experience Using a Novel All-Oral Treatment Regimen for Treatment of Rifampin-Resistant or Rifampin-Intolerant Tuberculosis Disease
Abstract Background Rifampin-resistant tuberculosis is a leading cause of morbidity worldwide; only one-third of persons start treatment, and outcomes are often inadequate. Several trials demonstrate 90% efficacy using an all-oral, 6-month regimen of bedaquiline, pretomanid, and linezolid (BPaL), but significant toxicity occurred using 1200-mg linezolid. After US Food and Drug Administration approval in 2019, some US clinicians rapidly implemented BPaL using an initial 600-mg linezolid dose adjusted by serum drug concentrations and clinical monitoring. Methods Data from US patients treated with BPaL between 14 October 2019 and 30 April 2022 were compiled and analyzed by the BPaL Implementation Group (BIG), including baseline examination and laboratory, electrocardiographic, and clinical monitoring throughout treatment and follow-up. Linezolid dosing and clinical management was provider driven, and most patients had linezolid adjusted by therapeutic drug monitoring. Results Of 70 patients starting BPaL, 2 changed to rifampin-based therapy, 68 (97.1%) completed BPaL, and 2 of the 68 (2.9%) experienced relapse after completion. Using an initial 600-mg linezolid dose daily adjusted by therapeutic drug monitoring and careful clinical and laboratory monitoring for adverse effects, supportive care, and expert consultation throughout BPaL treatment, 3 patients (4.4%) with hematologic toxicity and 4 (5.9%) with neurotoxicity required a change in linezolid dose or frequency. The median BPaL duration was 6 months. Conclusions BPaL has transformed treatment for rifampin-resistant or intolerant tuberculosis. In this cohort, effective treatment required less than half the duration recommended in 2019 US guidelines for drug-resistant tuberculosis. Use of individualized linezolid dosing and monitoring likely enhanced safety and treatment completion. The BIG cohort demonstrates that early implementation of new tuberculosis treatments in the United States is feasible.
The dependence of maximum oxygen uptake on hemoglobin-oxygen affinity and altitude: a computational modeling approach
Background: Hemoglobin, the primary oxygen-carrying protein in humans, provides the intermediate link between pulmonary oxygen uptake and tissue oxygen consumption. Oxygen transport is greatly influenced by the hemoglobin-oxygen affinity, which is commonly characterized by the metric P50 - defined as the oxygen tension at which 50% of hemoglobin is saturated. Humans with rare hemoglobin mutations causing a low P50 (high hemoglobin-oxygen affinity) have demonstrated remarkable preservation of exercise tolerance at high altitude conditions (~3,000m). However, the influence of a low P50 on V̇O2max at extreme altitudes (>5,500m) remains largely unexamined. To examine the dependence of V̇O2max on P50 and altitude, we developed a computational model of oxygen uptake and utilization. We hypothesized that a low P50 would result in a better maintained V̇O2max at extreme altitudes compared to conditions of normal P50 and high P50 (low hemoglobin-oxygen affinity). Methods: We created a model that couples pulmonary oxygen uptake with systemic oxygen utilization to estimate V̇O2max as a function of P50, hemoglobin concentration, and altitude. Fixed values for cardiac output and tissue oxygen demand for V̇O2max at sea level were assigned in accordance with experimental data. The pulmonary oxygen uptake model assumes a single blood compartment exposed to alveolar gas, from which the arterial oxygen tension may be estimated from venous input. Using the alveolar gas equation, we interpolated respiratory parameters from data obtained during human sojourn to the summit of Everest. The systemic oxygen utilization model uses arterial input parameters along with Michaelis-Menten kinetics to compute oxygen consumption. The Fick principle was used to determine the venous oxygen tension, which was assumed to approximate tissue oxygen tension. From these values, systemic oxygen extraction and V̇O2max were determined as a function of P50, hemoglobin concentration, and altitude. Results: We present the results for several cases of P50 (low, normal, and high) and hemoglobin concentrations as a function of altitude. For a low P50, the model demonstrated a greater arterial oxygen saturation, greater oxygen content, and lower systemic extraction at extreme altitudes compared to values determined for cases of normal and high P50. Additionally, a low P50 led to better maintenance of V̇O2max at ~8,850m (~38% decrease from sea-level V̇O2max) compared to values determined for normal P50 and high P50 (~53% and ~67% decrease from sea-level V̇O2max, respectively, P<0.05). Conclusion: This model demonstrates the importance of P50 in the determination of V̇O2max at various altitudes. At low altitudes, a low P50 does not confer an advantage in terms of oxygen utilization, likely due to diffusive oxygen limitations. However, at high and extreme altitudes, a greater convective oxygen transport associated with a low P50 likely outweighs impairments in oxygen diffusivity. This project was supported by the National Institutes of Health R-35-HL139854. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
Current Status and Challenges of Oncolytic Virotherapy for the Treatment of Glioblastoma
Despite decades of research and numerous clinical trials, the prognosis of patients diagnosed with glioblastoma (GBM) remains dire with median observed survival at 8 months. There is a critical need for novel treatments for GBM, which is the most common malignant primary brain tumor. Major advances in cancer therapeutics such as immune checkpoint inhibitors and chimeric antigen receptor (CAR) T-cell therapy have not yet led to improved outcomes for GBM. Conventional therapy of surgery followed by chemoradiation with or without tumor treating fields remains the standard of care. One of the many approaches to GBM therapy currently being explored is viral therapies. These typically work by selectively lysing target neoplastic cells, called oncolysis, or by the targeted delivery of a therapeutic transgene via a viral vector. In this review, we discuss the underlying mechanisms of action and describe both recent and current human clinical trials using these viruses with an emphasis on promising viral therapeutics that may ultimately break the field’s current stagnant paradigm.